<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        video {
            width: 1300px;
            height: 1000px;
            margin: 0 auto;
            outline: 1px solid rebeccapurple;
        }

        x:lang(wei) {
            width: 100px;
            height: 100px;
            outline: 1px solid red;
        }

        .sss {
            width: 10px;
            height: 50px;
            outline: 1px solid rgb(238, 255, 0);
        }
    </style>
</head>

<body>
<div onmousedown="mDown(this)" onmouseup="mUp(this)"
     style="background-color:#D94A38;width:90px;height:20px;padding:40px;">
    点击鼠标
</div>
<!-- <video width="400px" controls autoplay>
    <source src="../图片/流星2.mp4" type="video/mp4" >
        Your browser does not support HTML5 video.
</video> -->
<video autoplay="autoplay" muted="muted" loop='lomp' muted='muted' controls='controls' controlsList='nodownload'
       src="../图片/流星2.mp4">
</video>
<br>
<x lang="wei" onclick="xxx">这里是一个伪类</x>
<div class="sss"></div>
</body>

<script>
    // function mDown(obj) {
    //     obj.style.backgroundColor = "#1ec5e5";
    //     obj.innerHTML = "松开鼠标";
    // }

    function mUp(obj) {
        obj.style.backgroundColor = "#D94A38";
        obj.innerHTML = "谢谢您";
    }
</script>

</html>